Re: XPL query

[cld@xxxxxxxx (Carl Distefano)]

Reply to note from Harry Binswanger  Thu, 08 May
2003 14:20:46 -0400

> Can you advise on  vs. ?

They both read keyboard input, of course. Specifically, they read
the first (and only the first) character or function assigned to the
next pressed key. The difference is that  allows the entire key
assignment to execute;  allows the first char or func to execute
(unless you trap it in a Save/Get), but discards the rest. For
example, if the pressed key is configured thus:

nn=GT,N,e,w, ,Y,o,r,k

both > and > will save "GT" to Save/Get 01;
> will, additionally, allow "New York" to be written at
the cursor position.

Typically, you use  to solicit user input that's typed on the
CMline (because it allows the user to see what she's typing). You
use  to solicit the user's response to a menu of choices. It's
appropriate, for example, when you want to trap the key code
() or scan code () of the pressed key. Try running
this little demo several times, responding with different keys,
especially keys with complex key assignments:

XPLeNCODE v2.0
b-gin [UNTITLED]
{<}PR|Press a key{>}{<}SX01,{<}RK{>}{>};*;[cr|lf]{<}SX01,{<}V
A$KC{>}{>}{<}SX01,"You pressed key #"+{<}IS01{>}{>}{<}PR@01{>
}{<}EX{>}[cr|lf][cr|lf]
-nd
XPLeNCODE

Now run it again after substituting  for . See the
difference?

> how do you come up with these undocumented secrets?

You study other people's code. We learned a lot by poring over
XY4.DLG when it first appeared a dozen years ago. But mostly, you
experiment. How else?

--
Carl Distefano
cld@xxxxxxxx
http://users.datarealm.com/xywwweb/